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WO1990005340A1 - Systeme de controle d'acces a un ordinateur personnel - Google Patents

Systeme de controle d'acces a un ordinateur personnel Download PDF

Info

Publication number
WO1990005340A1
WO1990005340A1 PCT/US1989/004913 US8904913W WO9005340A1 WO 1990005340 A1 WO1990005340 A1 WO 1990005340A1 US 8904913 W US8904913 W US 8904913W WO 9005340 A1 WO9005340 A1 WO 9005340A1
Authority
WO
WIPO (PCT)
Prior art keywords
mov
computer
program
access
drive
Prior art date
Application number
PCT/US1989/004913
Other languages
English (en)
Inventor
Robert P. Lakoski
Roy Van Cleve, Jr.
Original Assignee
Lama Systems Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lama Systems Inc. filed Critical Lama Systems Inc.
Publication of WO1990005340A1 publication Critical patent/WO1990005340A1/fr

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
    • G06F21/70—Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer
    • G06F21/78—Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer to assure secure storage of data
    • G06F21/80—Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer to assure secure storage of data in storage media based on magnetic or optical technology, e.g. disks with sectors
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
    • G06F21/30—Authentication, i.e. establishing the identity or authorisation of security principals
    • G06F21/31—User authentication
    • G06F21/34—User authentication involving the use of external additional devices, e.g. dongles or smart cards

Definitions

  • This invention relates to computer
  • DOS - disk operating system - permits initialization of the computer for use with compatible software (MS DOS
  • LAMAINST.EXF the DOS program which installs the LAMASYS.SYS driver so that it will be initialized at boot time
  • BIOS keyboard service interrupts - a set of functions for reading the keyboard which are standardized as part of the .IBM standard
  • Hotkey - a user selected combination of keys used to invoke a program K equals thousand of bytes - exactly
  • RAM - random access memory - volatile loses contents when power is turned off
  • Periscope - a commercially available debugging system used by
  • ATTR.COM a commercially available program, distributed by PC
  • Hook - to redirect a system function call (such as keyboard) to one's own program to allow special handling before passing it on for normal system processing
  • Access control means a system which prevents the use of a personal computer by unauthorized personnel (persons who should not be accessing the personal computer).
  • full security may require audit trails, multiple permission levels, file and
  • Still another object of this invention is to provide an access control system which requires only a very small portion of computer memory for its operation.
  • Another object of this invention is to provide instant security screen activation upon keystroke command by the authorized user, and to return to the prior state, after the password is given.
  • Another object of this invention is to provide access control software coupled with a physical security boot drive slot blocking device to prevent introduction or removal of diskettes or cartridges from the drive slot when the physical blocking device is secured.
  • a computer access control system for use on a personal computer having a diskette boot drive device to deter unauthorized access to the computer data and programs, comprising physical means for blocking removal or insertion of diskette (operator removable medium) containing the computer boot drive device, and computer access control program means for enabling and disabling a personal computer upon input demonstrating authority to access the computer.
  • a method for controlling access to a personal computer with a diskette drive comprising the following steps: inserting a computer program containing device into the diskette data drive, blocking the drive with a lockable blocking device, installing a computer program including a device driver that is first addressed by the computer during boot up and which requires entry of a proper access code and password prior to moving to another device driver, and entering a selected access code and password.
  • This invention unites two previously independent access deterrent means, software and hardware, to provide access control that can be employed with confidence to prevent unauthorized access or use of a personal computer.
  • the software prevents unauthorized entry into the system both at time of initialization and during temporary breaks in the operator's work routine.
  • the combination of the hardware and software creates an intruder barrier prohibiting access, without damage, to the computer and with sounding of audible alarms if attempted surreptitiously.
  • the software described is for an embodiment directed for use with a MS-DOS or PC-DOS (2.0 or higher) based computer.
  • a MS-DOS or PC-DOS 2.0 or higher
  • the computer searches for a file called CONFIG.SYS which contains a list of "device drivers".
  • CONFIG.SYS contains a list of "device drivers”.
  • Each of these is loaded into memory and then given temporary control of the computer to allow initialization of the device it controls.
  • the access control .software for purposes of convenience is referred to as LAMASYS.
  • LAMASYS.SYS is a DOS device driver file which is activated at boot time as the first driver invoked by the CONFIG.SYS initialization process. It acts as an extension of the operating system, much like the console driver system included with PC-DOS.
  • LAMASYS.SYS driver is invoked prior to any other drivers. If the correct password and access code are not entered, the LAMASYS.SYS driver will not return control to the operating system, preventing initialization and any use of the computer. In addition, the driver continues to monitor the BIOS keyboard service interrupts, even after the computer begins normal operations. Any time a key is
  • the value of the returned keystroke is compared to a user-defined key (hotkey). If they match, the LAMASYS.SYS driver is invoked again.
  • the reliability of the access control governed by the software depends upon maintaining control of the disk drive which the computer uses for initialization. Generally, since personal computers attempt to initialize first from a
  • diskette if one can be found in drive A:, it is essential to block access to diskette Drive A:
  • Blocking access is achieved by use of ancillary locking hardware. More particularly, a disk drive lock is employed to block the diskette slot in such a way that a diskette may not be inserted into an empty drive or that a diskette locked into a drive will continue to function but may not be removed without causing visible damage to the computer or the hardware.
  • the software uses only 7K of memory, 4K of which are used to save the current screen data so that it can be restored later. While this is sufficient to store a normal 80x25 text screen, it does not provide enough memory to save a color graphics screen (16K bytes) or a 110x75 text screen, let alone some EGA graphics screens (256K). In balancing the competing principals, minimizing resident memory requirements versus complete screen text storage, the former was selected with the intent of saving as much screen area as can be saved in 4K and foregoing tying up memory.
  • the computer may be disabled at any time by the press of a user-selected "hotkey". Only entry of the correct password will return the computer to normal
  • the secured state may also be invoked from a batch file or from the DOS command line by use of the appropriate command file
  • the invention herein provides a computer access control system which does not in any way restrict or monitor the activities of authorized users once the appropriate log-on procedure has beenfollowed. Furthermore, the system neither restricts data files or directories nor does it restrict access to programs or count keystrokes. Indeed, it is a primary objective of the software in this invention to be as transparent as possible for the authorized user, and impossible for the unauthorized user. It is for this very reason that the software only requires 7K of resident memory, including 4K for screen storage. BRIEF DESCRIPTION OF THE DRAWING
  • Figure 1 is a schematic representation of a computer secured by the invention.
  • the invention includes hardware component 12 and software component 14 for use together on a multiple drive personal computer 10.
  • Software component 14 is an access control program.
  • the software for personal computers is stored on an insertable/removable medium such as floppy diskette 14 or alternatively, an optical disk or a RAM cartridge.
  • the computer includes disk drive unit 11 configured to receive the diskette (disk or
  • the hardware component may take the form of a portable disk drive locking unit of the type described in United States Patent 4,685,312 Lakoski et al, incorporated herein by reference.
  • the hardware can be of the form of a computer bezel mounted, lock and lock bar assembly described in Applicant's United States Patent
  • Both of the identified locking units are operated with a key. It is not intended to thus limit the invention to a combination lock or even a more sophisticated electronic locking means. As a practical matter, especially in a multiunit
  • the supervisor may possess a master key or duplicate key to unlock the
  • the second component of the system in one embodiment, is now described in detail as to its installation, operation and program content.
  • the program is configured and designed to operate on an IBM R personal computer or equivalent, using a
  • DOS Disk Operating System
  • IBM PC DOS IBM PC DOS or MS DOS version 2.0
  • the program supports both monochrome and color monitors and all conventional CGA and EGA graphic modes.
  • the program is capable of supporting non-standard screen dimensions as, for example, 132x44 characters, 110x75 or 80x66 modes of
  • the program for installation requires only 7K bytes of system RAM memory and only a 7.5K byte file on the boot diskette. If the DOS program is in a graphic mode when security is invoked, the security screen (described below) will be compressed. This is because only 4K of memory is used for saving the screen, so only 4K of the screen can be written over. In the high resolution EGA modes this
  • the next screen requests entry of a personal password, the second entry. This password must not be forgotten or the system can be locked out.
  • the user then has the option of selecting a "hotkey” (a key combination which immediately moves the system into the security mode as detailed below).
  • the "hotkey” initially is assigned the key combination "Ctrl 2". Once selection of the "hotkey” is complete, the user presses "6" to return to the Main Menu, then "5" to return to DOS. At this point, the user must reboot the computer with the ⁇ Ctrl> ⁇ AltxDel> keys for the invention's computer access control program to take effect.
  • the computer will now stop in the middle of the boot process and require the user to properly input the selected access code and password in order to continue. Once properly entered, the computer will continue booting in a conventional manner. Once the "hotkey" is entered, the same security screen appearing when booting, is viewed. Once the "hotkey" is entered, the same security screen appearing when booting, is viewed. Once the "hotkey
  • the installation method used by the execute program relies on the computer using the hard disk as the boot disk.
  • the intended "target” for the purpose of this program is identified in the first item in the main menu. This is the simplest of cases, since the same disk is both the "target" and the current
  • boot disk Other computer configurations, such as two floppy boot diskettes will require
  • LAMAINST will look for a hard disk drive which is the current "boot” disk in order to copy the current CONFIG.SYS file and to disable booting from that drive.
  • the end result is that the program will boot only from the specified floppy diskette and will complete booting as though it had booted from the original hard disk (if any).
  • This feature renders the computer access control program installation as transparent as possible. If a hard disk drive is available and specified, the installation program will simply use the specified drive instead of conducting a search for the drive containing the driver files. Unless a special configuration requiring manual override is involved, such specification is not necessary. In any case, the result is to copy the security driver file to the "target" disk and to modify the CONFIG.SYS file.
  • the boot disk may be specified by using the following command:
  • drive B is the target disk and that drive C:. is the current "boot disk”. Hence, drive C: is disabled from booting.
  • Selection of a specified drive copies the program on to the indicated drive and modifies the system files as needed. The user will be required to enter a new access code and password at this time. If the software is found to be already installed, a message will appear so indicating and the screen will return to the main menu.
  • the first option is the selection of a "hotkey".
  • the hotkey option is chosen the computer generates a sound and message.
  • a screen would read:
  • the audible bell sound is employed to inform the user that a particular key combination has been accepted. Not all keys work as "hotkeys" because some combinations cannot be sensed at this level of keyboard service. For example, ESCAPE cannot be used because it is used to escape from the menus of the access control program.
  • the user's selection of a hotkey combination should, in part, be governed by possible conflict with functional or essential command keys of the actual programs used. For this reason the use of the ⁇ Ctrl> and ⁇ Alt> keys and coupled with function or punctuation keys may prove the best combinations.
  • One further aspect of the hotkey is now discussed.
  • the security system will respond to the "hotkey” only when the active program actually requests a keystroke. This feature is to prevent the computer from being interrupted in the middle of critical operations, such as writing to the disk. There is a disadvantage; the system may not respond while involved in some tedious operation such as a spreadsheet recalculation. Also, in operation, the DOS program which can never see the "hotkey” since it is read by the security program may appear to be halted since it is still waiting for a keystroke which has never appeared. Pressing any key will allow the system to continue.
  • the presence of a hotkey is not required.
  • the program allows selection of a zero option which only invokes security at boot up. This program configuration, therefore, does not use any memory once the boot up security is completed.
  • a command is also provided for the user who may wish to restore the hotkey when the A> appears.
  • Screen color combination selections provide a highly visible indicator of the presource of a security screen.
  • the screen color selection option presents the user with an 8x16 grid
  • the cursor control keys are employed to move the cursor to a new color combination and press ⁇ Enter> to accept it.
  • ⁇ Escape> may be used to skip this process.
  • the only useful option here might be to select the black-on-black option for screen blanking purposes.
  • the next option permits the user to customize the security screen title.
  • the title line appears above the "AUTHORIZED PERSONNEL ONLY" banner. Up to 60 characters may be used for the title line. For convenience, due to internal programming, the resulting line will be properly centered on the screen. Since some CGA modes support only 40 columns of text, it is prudent to limit the title line to 40 characters or less when a color monitor is in use.
  • this option relating to the EGA and VGA high resolution graphics modes, the title never appears. This is because so little of the graphics screen can be preserved in the 4K of resident memory used for screen storage that there is simply not enough space to display the title.
  • Level 1 the system default level, is the least intrusive, but least secure level. It is usually adequate to maintain control unless a resident debugging system (such as "Periscope”) or other contentious resident programs, such as
  • the second level "steals" the system timer interrupts when the security screen is invoked.
  • the maximum security level, level 3 will disable even a hardware based debugging program such as "Periscope". When this security level is
  • This option selection of the alarm level will request the user to input a number between 1 and 9.
  • the inputted number will correspond to the number of incorrect password entry attempts allowed before the alarm is set off.
  • the default value here is three, which gives the authorized user a little latitude for error while providing the intruder with little room to experiment.
  • the final line in option menu inquires if the user wishes to return to the operating system. Once selected, the currently resident LAMASYS.SYS driver file is updated to reflect any changes to the options above. The computer and screen then returns to the original menu which allows the user to exit the installation program and return to the DOS command line. The user is cautioned since it is only after the computer is rebooted and the newly configured drive is reloaded that the inputted option changes will be fixed.
  • the access code must be entered exactly, including capitalization. As is the case with most programs, correction of erroneous input can be effected though the backspace key until the ⁇ Enter> key is pressed to complete the entry. Whatever the user types is visible at this point so that the state of the ⁇ Caps Lock> key can be verified, as well as the overall operation of the keyboard itself. Any key strokes beyond the twenty
  • Password entry is identical to access code entry, except that all typing is invisible. This is to prevent any casual observers from reading the password as it is being typed. If the access code and password are both correct, the screen will be restored to its original state and the boot process will continue. If either the Password or the Access Code is incorrect, the audio system will emit a less-than-encouraging sound. If the allowed number of incorrect entries has not been exceeded, the process starts over again at access code entry.
  • vandalism is intended the intruder can pry the physical locking device off of the computer and remove the software diskette or substitute his own diskette.
  • the removal of the access control program may be desired or even required at certain times. Since the configuration consists of the program system file in the root directory of the boot disk, the system may be effectively bypassed by removing either the system file or the first line of the CONFIG.SYS program. As a result of the system file normally being hidden, a utility file, such as the commercially available program ATTR.COM, is required to erase or rename the system file. Hence, it is often easier to erase the first line of the
  • the hard disk booting condition can be restored by renaming the command file (LCOMAND.COM) to its original name,
  • CONFIG.SYS FILE being hidden and renamed to CONFIG. SAV, it must be released and renamed to restore the computer to its pre-installation state. This requires a file utility program.
  • a programmer may be interested that manipulation of the DOS driver program allows for the invocation of the security screen from any DOS program.
  • the program "LAMA.COM” is included to allow security to be invoked from the DOS command line or from a batch file. It produces exactly the same effect as the "hotkey", a secured state.
  • This program might be to call it at the end of a long print run, when the user will be away from the computer.
  • Another use is as an Application in the Microsoft Windows environment, since resident utilities tend not to work there.
  • the following assembly language code demonstrates how the security screen can be called from any program by using the device driver
  • DOS open command with the name, 'LAMA1988' is entered. Functions 3, 5, 7, or 10 will activate the security screen. After control is returned, the device is closed in the normal manner. If the open command fails, the access program is not present.
  • DOS command line utility, LAMA.COM included on
  • vidregs.h.ah 3; /* read cursor position */ int86( 0x10, &vidregs, &vidregs );
  • vidregs.h.ah 3; /* read cursor position */ int86( 0x10, &vidregs, &vidregs );
  • pattptr pattern + 1 ;
  • hashptr &hashstr[0];
  • Iptr (long *) &hashstr[0];
  • strptr str
  • newptr StrFind (keystr, &lamabuffer, lamasize);
  • Iptr (long*) (basedata + 2 + usernum*8);
  • boxlen strlen(promptstr) +6;
  • Iptr (long*) (basedata + 2 + usernum*8);
  • target targetdisk - 'A'
  • Flnstall is called by the installation process to configure the system to boot from a floppy disk in drive A:. This copies and modifies the required files from the current boot drive.

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  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Theoretical Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Software Systems (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Storage Device Security (AREA)

Abstract

L'invention concerne un système protégeant l'accès à un ordinateur personnel, comportant un logiciel (14) de contrôle d'accès à protection à deux niveaux contre une défectuosité, une initialisation, empêchant l'accès à l'ordinateur sans l'entrée du code d'accès et du mot de passe, ainsi qu'un dispositif (12) de blocage physique d'une unité de disques pouvant être bloquée afin d'empêcher le retrait du logiciel (14) de l'ordinateur.
PCT/US1989/004913 1988-11-04 1989-11-03 Systeme de controle d'acces a un ordinateur personnel WO1990005340A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US26726588A 1988-11-04 1988-11-04
US267,265 1988-11-04

Publications (1)

Publication Number Publication Date
WO1990005340A1 true WO1990005340A1 (fr) 1990-05-17

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1989/004913 WO1990005340A1 (fr) 1988-11-04 1989-11-03 Systeme de controle d'acces a un ordinateur personnel

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AU (1) AU4622289A (fr)
WO (1) WO1990005340A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE9015869U1 (de) * 1990-11-20 1991-03-14 Inform Vertriebsgesellschaft für Kommunikationsanlagen und Sicherheitssysteme mbH + Co KG, 4000 Düsseldorf Sicherungsvorrichtung zum Sichern von Datenverarbeitungsanlagen
GB2253511A (en) * 1991-02-18 1992-09-09 John Hermann Eschenburg Protection device
GB2257194A (en) * 1991-06-26 1993-01-06 Roger William Solomon Harris Computer security device
EP0969345A1 (fr) * 1998-06-29 2000-01-05 PCS PC-Systeme Entwicklungs- und Produktionsgesellschaft mbH & Co. KG Ordinateur comprenant une protection avec autorisation

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5388156A (en) * 1992-02-26 1995-02-07 International Business Machines Corp. Personal computer system with security features and method

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US4131001A (en) * 1975-11-17 1978-12-26 Gotto Raymond John Method to prevent unauthorized use of cassette tape recorders and a device according to the method
US4218738A (en) * 1978-05-05 1980-08-19 International Business Machines Corporation Method for authenticating the identity of a user of an information system
US4439830A (en) * 1981-11-09 1984-03-27 Control Data Corporation Computer system key and lock protection mechanism
US4527405A (en) * 1983-04-25 1985-07-09 Renick William A Security lock for cassette recorders and cassette players or theft discouragement device for cassette recorders and cassette players
US4621321A (en) * 1984-02-16 1986-11-04 Honeywell Inc. Secure data processing system architecture
US4640106A (en) * 1985-02-05 1987-02-03 Z-Lock Company, Inc. Device for preventing unauthorized use of a cassette tape deck
US4652990A (en) * 1983-10-27 1987-03-24 Remote Systems, Inc. Protected software access control apparatus and method
US4655057A (en) * 1985-02-05 1987-04-07 Z-Lock Corporation Security device for a video cassette recorder or the like
US4685312A (en) * 1985-01-24 1987-08-11 Lama Tool Company Disk drive locking device
US4719566A (en) * 1985-10-23 1988-01-12 International Business Machines Corporation Method for entrapping unauthorized computer access
US4870591A (en) * 1987-08-24 1989-09-26 International Business Machines Corp. System for ensuring device compatibility

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US4131001A (en) * 1975-11-17 1978-12-26 Gotto Raymond John Method to prevent unauthorized use of cassette tape recorders and a device according to the method
US4218738A (en) * 1978-05-05 1980-08-19 International Business Machines Corporation Method for authenticating the identity of a user of an information system
US4439830A (en) * 1981-11-09 1984-03-27 Control Data Corporation Computer system key and lock protection mechanism
US4527405A (en) * 1983-04-25 1985-07-09 Renick William A Security lock for cassette recorders and cassette players or theft discouragement device for cassette recorders and cassette players
US4652990A (en) * 1983-10-27 1987-03-24 Remote Systems, Inc. Protected software access control apparatus and method
US4621321A (en) * 1984-02-16 1986-11-04 Honeywell Inc. Secure data processing system architecture
US4685312A (en) * 1985-01-24 1987-08-11 Lama Tool Company Disk drive locking device
US4640106A (en) * 1985-02-05 1987-02-03 Z-Lock Company, Inc. Device for preventing unauthorized use of a cassette tape deck
US4655057A (en) * 1985-02-05 1987-04-07 Z-Lock Corporation Security device for a video cassette recorder or the like
US4719566A (en) * 1985-10-23 1988-01-12 International Business Machines Corporation Method for entrapping unauthorized computer access
US4870591A (en) * 1987-08-24 1989-09-26 International Business Machines Corp. System for ensuring device compatibility

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE9015869U1 (de) * 1990-11-20 1991-03-14 Inform Vertriebsgesellschaft für Kommunikationsanlagen und Sicherheitssysteme mbH + Co KG, 4000 Düsseldorf Sicherungsvorrichtung zum Sichern von Datenverarbeitungsanlagen
GB2253511A (en) * 1991-02-18 1992-09-09 John Hermann Eschenburg Protection device
US5268809A (en) * 1991-02-18 1993-12-07 Eschenburg John H Protection device for a computer diskette drive
GB2257194A (en) * 1991-06-26 1993-01-06 Roger William Solomon Harris Computer security device
GB2257194B (en) * 1991-06-26 1994-06-01 Roger William Solomon Harris Computer security
EP0969345A1 (fr) * 1998-06-29 2000-01-05 PCS PC-Systeme Entwicklungs- und Produktionsgesellschaft mbH & Co. KG Ordinateur comprenant une protection avec autorisation

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Publication number Publication date
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